The present invention relates to methods and devices for generating a machining program.
Conventionally, a control device called an interactive NC device is known, as described in Japanese Examined Patent Publication No. 3-13023. The control device refers to a database in correspondence with a machining process designated by a machining program and thus automatically generates control instructions for a machine tool. More specifically, the control device acquires a process sequence, a target position, a final product shape and the like by means of the control program. The device then refers to the information about a tool, a tool pattern, and cutting conditions pre-registered in the database. In this manner, the control device automatically generates control instructions about axes X, Y, and Z and a main shaft configuring the machine tool, an auto tool changer (ATC), and coolant. Accordingly, this control device makes it possible to generate a machining program easily by simplifying the content of the program, which also simplifies the work of the program generator (the operator).
However, the conventional interactive NC device is incapable of generating a machining program for forming, for example, an eccentric pin of a crankshaft, which is a cut resulting portion projecting eccentrically between a pair of opposing surfaces and having a cross-sectional area smaller than the cross-sectional area of each of the opposing surfaces.
If the machining program for forming the eccentric pin of the crankshaft is generated using the EIA/ISO code, such generation of the program requires a relatively long time. Further, an experienced operator is needed for producing a tool path improving the machining efficiency or accuracy. Also, if an EIA program is generated using CAM, the operation requires work of an experienced operator consuming a relatively long time. In addition, a CAM adapted to a multitasking lathe is also necessary, which increases the costs.